Modern mobile devices integrate a variety of communication technologies with geopositioning technology and sensors. The communication technologies (e.g., cellular, Wi-Fi, Bluetooth) allow users to communicate with other users in a variety of operating environments. Geopositioning technologies allow users to receive detailed digital maps and location-based services. Various sensors integrated in the mobile device receive input from the operating environment and provide output for a variety of interesting and useful applications running on the mobile device. For example, an accelerometer can detect when a device is held in portrait or landscape orientation, and then adjust a user interface based on the detected orientation. Sensors, such as the accelerometer in Apple Inc.'s iPhone™ have also been used in games. The user manipulates the iPhone™ in response to game action, such as trying to guide a virtual ball through a virtual maze or steer a virtual car or boat through a virtual racetrack.